The present invention relates to a fan tray assembly for use in an electronic chassis and, in particular, to a fan tray apparatus and method for cooling electronic devices housed within the electronic chassis.
Conventional electronic chassis used for high-speed switching and networking applications typically are comprised of a metallic box-shaped card cage. Numerous circuit board modules (otherwise known as application cards) are slid into the electronic chassis along card guide assemblies, and are electrically attached to a backplane circuit board located along the backside of the chassis.
Each application card typically includes a large number of electronic components. As a result, these application cards generate a tremendous amount of heat, which must be removed from the chassis to protect the various electronic components within the chassis. As a result, conventional fans have been used to bring cooling air into the chassis, and, at the same time, to exhaust heated air from the chassis.
Various attempts have been made to reduce the temperature within an electronic chassis by providing a fan tray assembly, which includes one or more conventional fans. The fan tray assembly may then be housed within the chassis along the top portion of the chassis. Cool air is circulated upward from the bottom of the chassis, through the chassis between the card guide assemblies, and the heated air is exhausted out through the top of the chassis.
Electronic chassis typically have strict dimensional requirements. As a result, the size and orientation of the fans is critical to maximize the amount of airflow through the chassis. Conventional fan tray assemblies, however, typically have several drawbacks. For example, in an effort to increase the output of the cooling ability of the fans, which is necessary to prevent overheating of the electronic component within the chassis, most conventional designs have relied on the xe2x80x9cbigger is betterxe2x80x9d premise, and have increased the size of the fans themselves. However, this results in other problems, including an increase in the required space within the chassis (which is typically not feasible), an increase in the weight of the chassis beyond acceptable limits, an increase in the number of parts, and an increase in the cost of production.
Moreover, conventional fan tray assemblies typically do not provide the optimum orientation of the fans within the tray to maximize the airflow through the chassis. The layout of the fans within the fan tray is typically extremely important to minimize xe2x80x9cdead airxe2x80x9d zones within the chassis, and to supply adequate airflow to the higher impedance areas within the chassis, such as along the sides of the chassis and along the backplane circuit board.
Accordingly, it would be desirable to provide a fan tray apparatus and method that overcomes the disadvantages described above.
One aspect of the invention provides a fan tray apparatus including a mounting body portion having a length and a width. The mounting body portion further includes first and second longitudinal sides, and first and second lateral sides. A plurality of fans is operatively attached to the mounting body portion. The plurality of fans includes a first set of fans, a second set of fans, and a third set of fans. The first set of fans is positioned along the first lateral side, the second set of fans is positioned along the second lateral side, and the third set of fans is positioned between the first set of fans and the second set of fans. The third set of fans is positioned on a middle portion of mounting body portion. The third set of fans may preferably be spaced apart from the first set of fans a distance that is equal to a distance between the third set of fans and the second set of fans. The third set of fans may preferably be spaced apart from the first longitudinal side and the second longitudinal side. The first set of fans may preferably be comprised of at least three fans, the second set of fans may preferably be comprised of at least three fans, and the third set of fans may preferably be comprised at least two fans. The first and second set of fans may each be comprised of three fans, and the second set of fans may be comprised of two fans. Each of the plurality of fans may preferably be identical. Each of the plurality of fans may preferably include a length, a width, and a height. The length of each of the plurality of fans may preferably be 120 millimeters, the width of each of the plurality of fans may preferably be 120 millimeters, and the height of each of the plurality of fans may preferably be 38 millimeters.
A first circuit board may preferably be positioned on the mounting body portion along the second longitudinal side between the first, second, and third sets of fans. The first circuit board may preferably include redundant DC/DC converters. A controller printed circuit board for controlling the plurality of fans may preferably be positioned on the mounting body portion along the first longitudinal side between the first, second, and third sets of fans. A through opening may preferably extend through the first longitudinal side, and a connector may preferably extend through the opening and may preferably be attached to the first longitudinal side. The connector may preferably be electrically connected to the plurality of fans. The connector may preferably be a floating-blind mate connector. The second longitudinal side may preferably include a pair of manually operable latches. The mounting body portion may preferably include a plurality of grated openings wherein the plurality of grated openings is aligned with the plurality of fans. The mounting body portion may preferably include a plurality of mounting body portion fastener openings spaced apart along the first longitudinal side and the first and second lateral sides. A cover portion may also be provided, which is mounted to the mounting body portion. The cover portion may preferably include a plurality of cover fastener openings spaced apart along a perimeter portion of the cover portion wherein the cover fastener openings are aligned with the mounting body portion fastener openings. The cover portion may preferably include a plurality of fan openings that are aligned with the plurality of fans. Each of the plurality of fan openings may preferably be is circular.
Another aspect of the invention provides a method of orienting a fan tray. A mounting body portion having a length and a width is provided. The mounting body portion includes first and second longitudinal sides and first and second lateral sides. A plurality of fans is also provided. The plurality of fans includes a first set of fans, a second set of fans, and a third set of fans. The plurality of fans is attached to the mounting body portion. The first set of fans is positioned along the first lateral side, and the second set of fans is positioned along the second lateral side. The third set of fans is positioned between the first set of fans and the second set of fans. The third set of fans is positioned on a middle portion of the mounting body portion.
The invention provides the foregoing and other features, and the advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention and do not limit the scope of the invention, which is defined by the appended claims and the equivalents thereof.